Flash lamp usable both as a main and as a slave and connector therefor to an underwater camera

Abstract

A camera for underwater photography may be used together with one or more flash lamps each capable of serving both as a main lamp and as a slave. The camera is connected through its housing to a main lamp by way of an optical cable and when it is clicked, a control signal is emitted as a light signal and transmitted to the main lamp through the optical cable. The flash lamp has a photosensing unit for receiving a light signal and converting it into an electrical signal. A signal conversion circuit further converts this signal into a flash control signal by which the lamp flashes light. The photosensing unit is connected to the optical cable through a connector and receives light only through the cable when the connector is attached to it. When the lamp is used as a slave, the connector for the optical cable is detached from the photosensing unit and external light received through a transparent window is converted into an electrical signal for the emission of flash light.

What is claimed is: 
     
       1. A flash lamp for use both as a main and as a slave with a camera unit including a camera, said flash lamp comprising: a main housing which contains a flash light outputting part;   a light signal receiving part on said main housing, said light signal receiving part being detachably connectable to an optical cable for transmitting optical signals therethrough, said light signal receiving part having a transparent water-proof window and light sensor means inside said window for sensing light only through said optical cable when said optical cable is attached to said light signal receiving part, sensing light received through said window when said optical cable is detached from said light signal receiving part, and outputting an electrical detection signal in response to said sensed light; and   a signal conversion circuit for receiving said detection signal from said light signal receiving part and transmitting a flash control signal to said flash light outputting part to control light output from said flash light outputting part.   
     
     
       2. The flash lamp of claim 1 wherein said signal conversion circuit detects a sudden rise and a sudden fall of said sensed light. 
     
     
       3. A combined system for underwater photography comprising: a flash lamp;   a camera including an electrical signal emitting terminal which transmits an electrical flash-activating signal towards said flash lamp when said camera is clicked for exposure; and   a camera housing which contains said camera therein, is detachably connectable to said flash lamp and includes a signal converting circuit for receiving said flash-activating signal and correspondingly outputting a converted electrical signal and a cable connector for attaching said camera housing with an optical cable, said cable connector containing therein a light source for emitting a light signal through said optical cable in response to said converted electrical signal from said signal converting circuit; wherein said flash lamp comprises: a main housing which contains a flash light outputting part;   a light signal receiving part on said main housing, said light signal receiving part being detachably connectable to an optical cable for transmitting optical signals therethrough, said light signal receiving part having a transparent water-proof window and light sensor means inside said window for sensing light only through said optical cable when said optical cable is attached to said light signal receiving part, sensing light received through said window when said optical cable is detached from said light signal receiving part, and outputting an electrical detection signal in response to said sensed light; and   a signal conversion circuit for receiving said detection signal from said light signal receiving part and transmitting a flash control signal to said flash light outputting part to control light output from said flash light outputting part.     
     
     
       4. The combined system of claim 3 wherein said light source comprises a light-emitting diode. 
     
     
       5. The combined system of claim 3 wherein said flash-activating signal has two pulses separated by an intended time of exposure.